v0.2.6

• Fix: double-click editing (insert a shape vertex / split a break point) now works on OpenLayers and Leaflet — previously only MapLibre did. The capture-phase press handler that stops the map pan on a draggable hit was also suppressing the engine's synthesized dblclick, so it never reached the controller. OpenLayers now listens to the native viewport dblclick (its handles are canvas, so it fires reliably); Leaflet detects the double-click manually from press timing + position (its handle markers are recreated on every re-render, so the two clicks land on different DOM nodes and no native dblclick is emitted at all).
• Add: MapLibre call-out boxes — a 9-slice icon-text-fit background box drawn behind any label that carries textBackground, for parity with the native backgroundFill boxes on OpenLayers/Leaflet.
• Change: call-out box padding increased on OpenLayers and Leaflet; sprite glyphs in Leaflet divIcons now scale to (and centre within) the icon box instead of sitting at their intrinsic size; Leaflet multi-line labels honour \n (white-space: pre-line).